Microplastic Removal

Goal

Remove microplastic particles from water sources.

Problem

Microplastic pollution in oceans, rivers, groundwater and drinking water.

Concept Summary

Natural polysaccharide extracts from plants such as okra and fenugreek act as non-toxic flocculants. When added to water containing microplastics, the sticky biopolymers bind the particles, cause them to aggregate and sink, allowing easy separation of the plastics from the water.

Principles

• Flocculation
• Adsorption
• Aggregation
• Sedimentation

Scientific Domains

Materials

• Okra polysaccharide extract (powder)
• Fenugreek polysaccharide extract (powder)
• Cactus polysaccharide extract
• Aloe vera polysaccharide extract
• Tamarind polysaccharide extract
• Psyllium polysaccharide extract
• Polyacrylamide (synthetic flocculant, used for comparison)

Mechanisms of Action

• Polysaccharide chains adsorb onto microplastic surfaces
• Bridging between particles creates larger flocs
• Increased mass causes flocs to settle out of suspension

Applications

• Municipal wastewater treatment
• Industrial water recycling
• Drinking water purification

Claimed Performance

Up to 90 % removal of microplastics; 67 % (okra) and 93 % (fenugreek) removal in one hour; 70 % removal in 30 minutes with equal parts okra-fenugreek mixture.

Experimental Evidence

Lab tests in pure water, ocean water, freshwater and groundwater showed high removal efficiencies; microscopy images confirmed floc formation and microplastic capture.

Limitations

• Scale-up from laboratory to field conditions not demonstrated
• Effectiveness may vary with water chemistry and microplastic type
• Cost and logistics of large-scale plant extract production
• Potential need for downstream removal of floc sediment

Keywords

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